Some better control for filenames in title formatting
Right now, the only option for displaying the current image's name in the title are the %f/%F flags, which have some shortcomings. Despite being documented as the "bare filename", they strip away the file extension, enclose it in square brackets, and add on import/export status if it's not a GIMP file. This is a lot to pack in with what's supposed to just be a filename; it might be nicer if there could be a bit more command over this some way or other.